The resolution of colour and
greyscale pictures should be twice the desired screen
ruling. In other words, when printing with screen ruling 60
lines per cm, the image resolution should be 120 pixels per
centimetre or 300 dpi. In scanning it is advisable to even higher
values for the image to endure more stripping and manipulation.
On the monitor screen a 1:1 image is fairly
large because of the low resolution of the monitor. A 300
dpi picture is shown more than four times larger in order for a 72
dpi screen to be able to reproduce all pixels.The resolutions
of imagesetters and platesetters are very high, even 2000 to
5000 dpi. The higher the resolution, the more greyscale levels can
be reproduced; however, even for this an optimal value can be
calculated.
